Process of and compound for treating rubber



Patented Sept. 20, 1932 UNITE -stares ATEN'H O F' L GEORGE STAFFORD WHI'IBY, on MONTREAL, UE EC, CANADA, nssIGNoR' TO THE,

ROESSLER & EAssL'AcHER CHEMICAL COMPANY, or NEW YORK, N; Y., A conronm TION OF DELAWARE Houses on AND 'ooixrrouunrort sanguine nuserm.

No Drawing. Application filed November 22, 1930,'Ser i a1 No-. 497 ,5 9 8, and in Great Britain July 18, 1930.

react an alkali metal salt of mercapto-benzo thiazole with hexamethylene tetramine ben- 15 zyl chloride to obtain a new compound which I I believe to be the hexamethylene tetramine benzyl ester of mercapto' benzo thiazole.

" One object of my invention isto" accelerate the rate of vulcanization of rubber and sulg phur mixtures, at'the same time producing. a a vulcanized product havlng improved ten- .sile strength andother desirable mechanical properties; This object is attained through Ithe use of my new compounds, and particu- 125 larlybythe useof the reaction productof hexamethylene tetramine, benzyl chloride with a salt'of mercapto benzo thiazole, as describedmore 'fully below." 7 r The 'hexamethylene tetramine benzyl ester goof. merca-pto'benzo thia' zole has the advantage of being a solid crystalline substance which can be'readily and easily incorporated into a" p rubber mix. Furthermore, its melting point issufficiently high so that it remains a solid, even in hot weather, and does not agglomer ate or become sticky as do many other ac-v l celerators. Other properties of my 'acceler-r ators which make them "desirable are, that they can be used at both high and low tem peratures; their acceleration of vulcanization is very rapid, they work well with carbon black stocks, so called non-blooming products'can easily be made by' their use;

and they can be made at low cost;

I gram'sfof thevsodium salt of mercaptobenzo thiazole was mixed with anFaqueous solution 7 9015 13.3 grams of the benzyl chloride addition 1 The following example will serve to illus- I product of hexamethylenetetramine. After" stirrlng for'some time, theturbid mixture 'became clear and grams of a light yellow solid separated; This crude product was re crystallized from alcohol giving a pale yel low crystalline powder which melted at 140 C. v

Other saltsof mercapto benzothiazole may be used, with the benzyl chloride addition product, but I prefer the use of therelatively mexpensive and easily prepared sodium salt.

- The product of this reaction has a definite melting point and I believe the reaction which takes place may be represented by the following equation: I

I therefore refer to this new product as the hexamethylenetetram'ine benzyl ester of mercapto benzothiazole; that is, hexamethylene-. tetramine benzyl mercapto behzothiazoleQ The following examples illustrate the use of the product ofthe above reaction in the vulcanization, of rubber Example I 7 Ingredients Parts Rubber 10D Zinc oxide.-- 5 su1 11ur V5 Hexamethylenetetramine benzyl mercaptobenzo thiazolen After milling these ingredients together, the mix was vulcanized at'a temperaturecorresponding to steam at 20v lbs. pressure. The 0 resulting vulcanized product when tested gave the following results:

. a j OOOper V a Cure Stretch Set fii Tensile 1 tion 1 Pounds TQZLGTG, Minutes 7 V. V o inch is a a as a loo Ebcample I I This example illustrates the use of my accelerators in tire tread stock.

ingredients 7 Smoked sheet rubber- Hexamethylenetetramine benzyl ruercentobenzo thiazo1e 1 This mix was vulcanized at a temperature corresponding to 30 lbs. steam pressure. The

resulting vulcanized product gave the i501- lowing results whentested'zi 8 th 400 tier j vre c cen v Cure (per cent) 610mg:v Tensile r V 7 tion P Pounds Y PCTXQ'IMZTP 7 Minutes i'nch 20 630 1500 3160 3() 620 11700 3434 40 610 1800 3488 The tabulation belotv further illustrates the use of my accelerators as applied to'tire tread stocks and serves to show by way of Table 1 Load to pro- V duce Tensile Material 7 Meltingpoint Stretch 600 per strength cent (pounds) V elongation H Percent, 7 1. Hexa benzyl 5 methyl Soft resin. 740 1450 3848 .mercapto benzothiazole. V r 1 x H 2. Eexa benzyl 5 phenyl 71-2 760 1400 3905 mercaptobenzothiazole. V

3. Hexa benzy] 3 methyl 122-26" 770 1250 3919 mercapto benzothiazole. I

4;Hexa benzyl di mer- Decoinposed. 900 600 3157 capto benzothiazole.

5. Bexa benzy] 4 and 6 Resin 59-64 '700 1400 2981 methyl mercapto benzothiazole. l

6. Here benzyl mercapto 91,-3" 710 1 1800 3848 beta naptho thiazole. j

7. Hexe. benzyl mercapto 92-95 760 1400 3878 alpha naptho thiazole.

8. Hem benzyl 5 nitro -106-'10 750 1300 3372 mercapto benzo-thiazzole; 1 r I 9. Hexa benzyl dimethyl 62110 740 1300 3768 mercafitobenz'othiazoie. g

10. Bexa; benzyl 5 amino 175-9 860 700 3313 mercapto benzothiezole Smoked sheet example some of the numerous compounds embodied by my invention.

Formula used in tests Zinc oxides These'mixes were vulcanized for 30 minutes at 40 lbs. steampressure With results when tested as given inthetable:

My accelerators not only make possible the production in a very short curing time and canized.

9. Theprocess o jposltion compr sing incorporating with unvulcanized rubber a vulcanizin'g agent and the at a low temperature, of vulcanized rubber of great toughness, tensile strength, and resistance to abrasion, When used alone, but tend to produce results of the same superior v nature Whenufsed with other accelerators and rubber compounding ingredients They produce better results and are more economical to use than hexamethylenetetram ne or mercaptobenzothiazole; .7

The amount of new accelerators necessary to be incorporated into the rubber to obtain the above described superior results.

Will generallyamountto less than 1% and more than of the weightof the rubber used. Lessor greater amounts of accelerator thalr to 1% will, of course, give simi lar resu'lts,'the exact amount for the bestresults depending upon the nature and amounts oif'th'e other ingredients of the mix to-be vul- Claimsr 1. The process for the preparationof'the hexamethylene tetramine. benzyl esterofa mercapto thiazolefvvhich comprises reacting the addition product of a benzyl halide'and hexarnethylene tetramine With a metal salt of a'mercapto thia'zole.

, 2. The process for the preparation of the hem-methylene 'tetramine benzyl ester of a S substituted "mercapto thiazole I which. comprises reacting'the addition product of ben- .zyl v chloride and hex'alnethyleiie tetramine with thesodium s altj ofa substituted mercapto thia'zole.

3. The process'for the preparation "of the ,hexa'methylene tetramine ester of a mercapto thiazo'le comprising reacting the addition product of benzyl chloride andhexameth'yh ene tetramine with a metal sale of an aryl inercapt'o thiazole'.

. 4. The process for the preparation the prises reacting the addition product of benzyl chloride and hexamethylene tetraminewith the :sodium salt of a substituted aryl mercapto thiaz ole.

"reaction product of hexamethylene tetr'amine 'be'nzyl chloride and. a metal's'alt of amercapto thiazole.

7. As a] new; composition of matter, the

hexameth'y'lene tetramine benzylester of an aryl mercapto'thiazole.

8. As a new compositionof matter, the 're-' action product ofheXamethylene tetramine.

benz'yl chlorideandc-a metal salt of an'jaryl mercapto thiazole; V L" fprepar nga rubber comproduct resulting from reacting hez'zainethylhexamethylene tetramine benzyl'ester of a substituted .mercapto .thia'zole I which comene tetramine benzyl chloride with a metal salt of a mercapto thiazole, and, thereafter, vulcanizing.

10. The process of preparing a rubber composition comprising incorporating with unvulcanized rubber a vulcanizing agent and the product resulting from reacting hexamethylene tetramine benzyl chloride with a metal salt of anaryl mercapto thiazole, and,

thereafter, vulcanlzing.

11. The process of preparing a rubber composition comprising vulcanizing rubber in the presence of the hexamethylene tetramine benzyl ester of a mercapto naptho thiazole.

12. As a new composition of matter, the V hexamethylene tetramine benzyl ester of a mercapto naptho thiazole.

13. As a new composition oft-matter, the reaction product of hexamethylene tetramine benzyl chloride and a metal salt of a mercapto naphtho thiazole.

14;. A rubber composition resulting from the vulcanization of a rubber mix comprising a product as set forth in claim 5.

15.- A rubber composition resulting from the vulcanization of a rubber mix comprising a product as set forth in claim 6.

16. A rubber composition resulting from the vulcanization of a rubber mix comprising the product obtained when hexamethylenetetramine benzyl halide is reacted with the metal salt of a mercaptothiazole 17. A rubber composition resulting from it the vulcanization of a rubber mix comprising i the product obtained when hexamethylenetetramine benzyl chloride is reacted with the sodium salt of a mercapto naptho thiazole.

Signed at Toronto, Canada, this 18th day of November A. D. 1930.

GEORGE STAFFORD WHITBY,

CERTIFICATE OF CORRECTION.

Patent No. 1,878,655. September 20, 1932.

GEORGE STAFFORD WHITBY.

It is hereby certified that error appears in the printed specification of the above numbered-patent requiring correction as follows: Page 2, line 103, claim 3, for "chloride" read halide; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 29th day of November A. D. 1932.

M. J. Moore, (Seal) Acting Commissioner of Patents. 

